Identifying climate change hotspot regions is critical for planning effective mitigation and adaptation activities. We use standard Euclidean distance (SED) to calculate integrated changes in precipitation and temperature means, interannual variability, and extremes between different future warming levels and a baseline period (1995–2014) using the Coupled Model Intercomparison Project Phase 6 (CMIP6) climate model ensemble. We find consistent hotspots in the Amazon, central and western Africa, Indonesia and the Tibetan Plateau at warming levels of 1.5°C, 2°C, and 3°C for all scenarios explored; the Arctic, Central America and southern Africa emerge as hotspots at 4°C warming and at the end of the 21st century under two Shared Socioeconomic Pathways scenarios, SSP3-7.0 and SSP5-8.5. CMIP6 models show higher SED values than CMIP5, suggesting stronger aggregated effects of climate change under the new scenarios. Hotspot time of emergence (TOE) is further investigated; TOE is defined as the year when the climate change signal first exceeds the noise of natural variability in 21st century projections. The results indicate that TOEs for warming would occur over all primary hotspots, with the earliest occurring in the Arctic and Indonesia. For precipitation, TOEs occur before 2100 in the Arctic, the Tibetan Plateau and Central America. Results using a geographical detector model show that patterns of SED are shaped by extreme hot and dry occurrences at low-to-medium warming, while precipitation and temperature means and extreme precipitation occurrences are the dominant influences under the high emission scenario and at high warming levels.

中文翻译：

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21世纪不同变暖情景下未来气候变化热点

确定气候变化热点区域对于规划有效的减缓和适应活动至关重要。我们使用标准欧几里得距离 (SED) 来计算降水和温度均值、年际变化以及不同未来变暖水平和基线期（1995-2014）之间的极端值的综合变化，使用耦合模型比对项目第 6 阶段 (CMIP6) 气候模型合奏。我们在亚马逊、非洲中部和西部、印度尼西亚和青藏高原发现了一致的热点，在所有探索的情景中，升温水平分别为 1.5°C、2°C 和 3°C；在 SSP3-7.0 和 SSP5-8.5 两种共享社会经济路径情景下，北极、中美洲和南部非洲在升温 4°C 和 21 世纪末成为热点。CMIP6 模型显示出比 CMIP5 更高的 SED 值，表明在新情景下气候变化的综合影响更强。热点出现时间（TOE）得到进一步研究；TOE 被定义为气候变化信号首次超过 21 世纪预测中自然变率噪声的年份。结果表明，变暖的 TOE 将发生在所有主要热点地区，最早发生在北极和印度尼西亚。对于降水，TOE 发生在 2100 年之前的北极、青藏高原和中美洲。使用地理探测器模型的结果表明，SED 的模式受中低升温条件下极端炎热和干燥事件的影响，而降水和温度均值和极端降水事件是高排放情景和高升温水平下的主要影响因素.